The existing Velocity logic was pretty optimistic, hoping the player connection would stay alive long enough to accept a connection to another server. Now, if we notice a read timeout on the server end, we'll treat the disconnect as "unsafe" and disconnect the player immediately.
I've added a configuration option to solve the issue in the way BungeeCord does it. This could cause issues with servers that extensively modify the server pipeline and could degrade the user experience, though. Let's try this more conservative and see if it helps,
Add log4j.skipJansi to prevent Log4j from initializing a Jansi
terminal. It is redundant because this is handled by TCA and it
will be only active for a few seconds until TCA is loaded.
The Velocity API has had a lot of community input (special thanks to @hugmanrique who started the work, @lucko who contributed permissions support, and @Minecrell for providing initial feedback and an initial version of ServerListPlus).
While the API is far from complete, there is enough available for people to start doing useful stuff with Velocity.